Retry logs write when it fails.
Report skipped event in statsd.

Test: manual test
BUG: b/77222120
Change-Id: I257f5e76d557893c4eb4a8e8a13396d8b5d1afc0
diff --git a/cmds/statsd/src/StatsLogProcessor.cpp b/cmds/statsd/src/StatsLogProcessor.cpp
index de8dfe4..de4ab63 100644
--- a/cmds/statsd/src/StatsLogProcessor.cpp
+++ b/cmds/statsd/src/StatsLogProcessor.cpp
@@ -158,7 +158,10 @@
 void StatsLogProcessor::OnLogEvent(LogEvent* event) {
     std::lock_guard<std::mutex> lock(mMetricsMutex);
     const int64_t currentTimestampNs = event->GetElapsedTimestampNs();
+
     if (currentTimestampNs < mLastLogTimestamp) {
+        StatsdStats::getInstance().noteLogEventSkipped(
+            event->GetTagId(), event->GetElapsedTimestampNs());
         return;
     }
 
diff --git a/cmds/statsd/src/guardrail/StatsdStats.cpp b/cmds/statsd/src/guardrail/StatsdStats.cpp
index 0c076e9..2315eaa 100644
--- a/cmds/statsd/src/guardrail/StatsdStats.cpp
+++ b/cmds/statsd/src/guardrail/StatsdStats.cpp
@@ -49,17 +49,21 @@
 const int FIELD_ID_ANOMALY_ALARM_STATS = 9;
 // const int FIELD_ID_PULLED_ATOM_STATS = 10; // The proto is written in stats_log_util.cpp
 const int FIELD_ID_LOGGER_ERROR_STATS = 11;
-const int FIELD_ID_SUBSCRIBER_ALARM_STATS = 12;
+const int FIELD_ID_PERIODIC_ALARM_STATS = 12;
+const int FIELD_ID_SKIPPED_LOG_EVENT_STATS = 13;
 
 const int FIELD_ID_ATOM_STATS_TAG = 1;
 const int FIELD_ID_ATOM_STATS_COUNT = 2;
 
 const int FIELD_ID_ANOMALY_ALARMS_REGISTERED = 1;
-const int FIELD_ID_SUBSCRIBER_ALARMS_REGISTERED = 1;
+const int FIELD_ID_PERIODIC_ALARMS_REGISTERED = 1;
 
 const int FIELD_ID_LOGGER_STATS_TIME = 1;
 const int FIELD_ID_LOGGER_STATS_ERROR_CODE = 2;
 
+const int FIELD_ID_SKIPPED_LOG_EVENT_STATS_TAG = 1;
+const int FIELD_ID_SKIPPED_LOG_EVENT_STATS_TIMESTAMP = 2;
+
 const int FIELD_ID_CONFIG_STATS_UID = 1;
 const int FIELD_ID_CONFIG_STATS_ID = 2;
 const int FIELD_ID_CONFIG_STATS_CREATION = 3;
@@ -346,6 +350,15 @@
     mPushedAtomStats[atomId]++;
 }
 
+void StatsdStats::noteLogEventSkipped(int tag, int64_t timestamp) {
+    lock_guard<std::mutex> lock(mLock);
+    // grows strictly one at a time. so it won't > kMaxSkippedLogEvents
+    if (mSkippedLogEvents.size() == kMaxSkippedLogEvents) {
+        mSkippedLogEvents.pop_front();
+    }
+    mSkippedLogEvents.push_back(std::make_pair(tag, timestamp));
+}
+
 void StatsdStats::noteLoggerError(int error) {
     lock_guard<std::mutex> lock(mLock);
     // grows strictly one at a time. so it won't > kMaxLoggerErrors
@@ -368,6 +381,7 @@
     mAnomalyAlarmRegisteredStats = 0;
     mPeriodicAlarmRegisteredStats = 0;
     mLoggerErrors.clear();
+    mSkippedLogEvents.clear();
     for (auto& config : mConfigStats) {
         config.second->broadcast_sent_time_sec.clear();
         config.second->data_drop_time_sec.clear();
@@ -491,6 +505,9 @@
         strftime(buffer, sizeof(buffer), "%Y-%m-%d %I:%M%p\n", error_tm);
         fprintf(out, "Logger error %d at %s\n", error.second, buffer);
     }
+    for (const auto& skipped : mSkippedLogEvents) {
+        fprintf(out, "Log event (%d) skipped at %lld\n", skipped.first, (long long)skipped.second);
+    }
 }
 
 void addConfigStatsToProto(const ConfigStats& configStats, ProtoOutputStream* proto) {
@@ -617,8 +634,8 @@
     }
 
     if (mPeriodicAlarmRegisteredStats > 0) {
-        uint64_t token = proto.start(FIELD_TYPE_MESSAGE | FIELD_ID_SUBSCRIBER_ALARM_STATS);
-        proto.write(FIELD_TYPE_INT32 | FIELD_ID_SUBSCRIBER_ALARMS_REGISTERED,
+        uint64_t token = proto.start(FIELD_TYPE_MESSAGE | FIELD_ID_PERIODIC_ALARM_STATS);
+        proto.write(FIELD_TYPE_INT32 | FIELD_ID_PERIODIC_ALARMS_REGISTERED,
                     mPeriodicAlarmRegisteredStats);
         proto.end(token);
     }
@@ -640,6 +657,15 @@
         proto.end(token);
     }
 
+    for (const auto& skipped : mSkippedLogEvents) {
+        uint64_t token = proto.start(FIELD_TYPE_MESSAGE | FIELD_ID_SKIPPED_LOG_EVENT_STATS |
+                                      FIELD_COUNT_REPEATED);
+        proto.write(FIELD_TYPE_INT32 | FIELD_ID_SKIPPED_LOG_EVENT_STATS_TAG, skipped.first);
+        proto.write(FIELD_TYPE_INT64 | FIELD_ID_SKIPPED_LOG_EVENT_STATS_TIMESTAMP,
+                    (long long)skipped.second);
+        proto.end(token);
+    }
+
     output->clear();
     size_t bufferSize = proto.size();
     output->resize(bufferSize);
diff --git a/cmds/statsd/src/guardrail/StatsdStats.h b/cmds/statsd/src/guardrail/StatsdStats.h
index 00bef75..93f780c 100644
--- a/cmds/statsd/src/guardrail/StatsdStats.h
+++ b/cmds/statsd/src/guardrail/StatsdStats.h
@@ -105,6 +105,8 @@
 
     const static int kMaxLoggerErrors = 10;
 
+    const static int kMaxSkippedLogEvents = 200;
+
     const static int kMaxTimestampCount = 20;
 
     const static int kMaxLogSourceCount = 50;
@@ -270,6 +272,11 @@
     void noteLoggerError(int error);
 
     /**
+     * Records statsd skipped an event.
+     */
+    void noteLogEventSkipped(int tag, int64_t timestamp);
+
+    /**
      * Reset the historical stats. Including all stats in icebox, and the tracked stats about
      * metrics, matchers, and atoms. The active configs will be kept and StatsdStats will continue
      * to collect stats after reset() has been called.
@@ -324,6 +331,9 @@
     // Logd errors. Size capped by kMaxLoggerErrors.
     std::list<const std::pair<int, int>> mLoggerErrors;
 
+    // Skipped log events.
+    std::list<const std::pair<int, int64_t>> mSkippedLogEvents;
+
     // Stores the number of times statsd modified the anomaly alarm registered with
     // StatsCompanionService.
     int mAnomalyAlarmRegisteredStats = 0;
diff --git a/cmds/statsd/src/stats_log.proto b/cmds/statsd/src/stats_log.proto
index 4aa3c973..8213252 100644
--- a/cmds/statsd/src/stats_log.proto
+++ b/cmds/statsd/src/stats_log.proto
@@ -292,4 +292,15 @@
         optional int32 error_code = 2;
     }
     repeated LoggerErrorStats logger_error_stats = 11;
+
+    message PeriodicAlarmStats {
+        optional int32 alarms_registered = 1;
+    }
+    optional PeriodicAlarmStats periodic_alarm_stats = 12;
+
+    message  SkippedLogEventStats {
+        optional int32 tag = 1;
+        optional int64 elapsed_timestamp_nanos = 2;
+    }
+    repeated SkippedLogEventStats skipped_log_event_stats = 13;
 }